This invention relates to a simply designed, constructed and maintained four-wheel sprocket drive crawler tractor.
Previous art discloses four-wheel drive apparatuses using a hydraulic pump and a hydraulic motor in U.S. Pat. No. 3,865,208 where a flow equalizer and/or a distribution box are utilized.
Means utilizing tension springs or screws to keep the track properly tension are well known in the industry, see for example, U.S. Pat. No. 1,079,164 and U.S. Pat. No. 3,082,044.
Certain farming rubber wheel tractor vehicles have provided means through extensions of the axle for the positioning of rubber tires to correspond to crop spacing.
Separate devices interconnected in the fluid line are well known in prior art for cooling the hydraulic fluid.